槽口宽度对伺服永磁电机齿槽转矩的影响研究

以利用能量法的解析模型计算抑制伺服永磁电机齿槽转矩的最佳槽口宽度,利用有限元法求解齿槽转矩,分析了解析法与有限元法数值求解结果出现误差的原因,探究了不同槽口宽度与齿槽转矩的关系。结果表明,齿槽转矩随着槽口开口长度的增加先增大后减小,当其取值在能量法计算的最佳槽口宽度附近时,齿槽转矩下降,符合理论预测,但是二者的极值点出现处存在0.41 mm的误差。针对槽口宽度过小导致下线困难的问题,对能量法的解析模型进行了改进,提出了以线径作为槽口宽度,探究槽口增加量与齿槽转矩变化的关系,确定最佳槽口增加量。结果表明,当最佳槽口增加量为1.2 mm,槽口宽度为2.35 mm,此时齿槽转矩为17.8 mN·m。

A Study on the Influence of Slot Width on the Cogging Torque of Servo Permanent Magnet Motors

The analytic model of the energy method is used for the calculation of the optimal slot width for suppressing cogging torque of the servo permanent magnet motors, followed by an analysis of the reasons for the errors in the numerical results of the analytical method and the finite method by using the finite element method to solve the cogging torque, with a tentative inquiry into the relationship between the width of different slots and the cogging torque. The cogging torque increases first and then decreases with the increase of the slot opening length. With its value approaching near the optimal slot width calculated by the energy method, the cogging torque decreases, which result is in line with the theoretical prediction, while with an error of 0.41 mm at the extreme point. In view of the flaw of offline difficulty resulting from too small groove widths, an improvement has thus been made in the analysis model of energy method, with the line diameter used as the slot width to explore the relationship between the optimal slot increment and the change of the slot torque. With the value of the optimum notch increase being 1.2 mm, the optimum notch width is 2.35 mm, and the cogging torque is 17.8 mN·m.